Fogged direct positive silver halide emulsion containing a sulfonatedtriphenylmethane dye

ABSTRACT

A direct positive photographic silver halide material containing in a silver halide emulsion layer and/or its adjacent layer a compound represented by the following general formula (I)   in which R may be the same or different and is selected from the group consisting of H, CH3, C2H5, and R&#39;&#39; is selected from the group consisting of H, CH3 and Cl, and S is selected from the group consisting of SO3H, and the alkali metal salts thereof and the ammonium salt thereof, and wherein the number of S substituents ranges from 1 to 3, is disclosed.

United States Patent 1 1 Kamano et a1.

11 3J3fid6 June 12, 1973 FOGGED DIRECT POSITIVE SILVER HALIDE EMULSION CONTAINING A [73] Assignee: Fuji Photo Film Co., Ltd., Kanagawa, Japan Filed: Apr. 14, 1971 Appl. No.: 134,046

[30] Foreign Application Priority Data Apr. 14, 1970 Japan 45 311354 US. Cl. 96/139, 96/101, 96/120,

96/64 Int. Cl G03c l/08 Field of Search 96/101, 139, 120,

References Cited UNITED STATES PATENTS 11/1966 Takao et a1 96/101 X 12/1949 Stauffer et a1. 96/64 10/1958 Landow 96/101 X Primary Examiner.1. Travis Brown Assistant Examiner-Won H. Louie, Jr. Att0rneySughrue, Rothwell, Mion, Zinn & Macpeak Inventors: Hideo Kamano; Hirotetu Kato; T.-

[57] ABSTRACT A direct positive photographic silver halide material containing in a silver halide emulsion layer and/or its adjacent layer a compound represented by the following general formula (I) R s S R i in which R may be the same or different and is selected from the group consisting of H, CH C 11 and R is selected from the group consisting of H, CH and Cl, and S is selected from the group consisting of SO H, and the alkali metal salts thereof and the ammonium salt thereof, and wherein the number of S substituents ranges from 1 to 3, is disclosed.

7 Claims, No Drawings BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a direct positive photographic silver halide material. More particularly, this invention is concerned with a direct positive photo'- graphic silver halide material whereby a direct positive having a high contrast and high reversal sensitivity and excellent sharpness and being free from residual colors can be obtained using one exposure and one developing treatment.

2. Description of the Prior Art It is well known that, in the production of a photographic light-sensitive material of the direct positive kind, the reversal sensitivity is raised markedly by adding -a d'esensitizer or a sensitizer to a previously fogged emulsion and the sharpness of an image is improved by preventing irradiation or halation of an emulsion layer.

As the above mentioned sensitizer are known organic compounds such as pinakryptol yellow, pinakryptol green and fuchsine (US. Pat. No. 2,857,273), and compounds containing metals of Group VIII of the Periodic Table, such as rhodium compounds and iridium compounds (US. Pat. No. 2,717,833), and as the sensitizing dye are known cyanine and merocyanine dyes.

There are various antihalation dyes for photographic light-sensitive materials yet not as many anti-halation dyes for direct positive light-sensitive materials.

It is a principal object of the invention to produce a direct positive photographic silver halide material having a high reversal sensitivity, an excellent image sharpness, and a high contrast and which is free from residual colors.

SUMMARY OF THE INVENTION This object can be accomplished by incorporating in an emulsion layer and/or an adjacent layer a dye represented by the following general formula:

in which R may be the same or different and represents H, Ch C l-I or R represents H, CH or C1, and S represents SO H or its alkali metal salt or ammonium salt, the number of S being 1 to 3.

DESCRIPTION OF THE INVENTION Examples of compounds which can be used in the invention are given as follows:

As is well known, these compounds can be prepared by sulfonating a triphenylmethane dye with fuming sulfuric acid, (e.g., Color Index No. 42650, 42745, 42735, 42685, 42690 and 42695).

It is now found that the compounds represented by the above described general formula have no influence on ordinary silver halide emulsions, but, for direct positive silver halide emulsions, they are able to sensitize spectrally and to raise the reversal sensitivity markedly.

Up to the present time, a desensitizer, a sensitizing dye and an antihalation dye, i.e. three types of chemicals have been used, but, when using the abovedescribed compound, only one type serves to accomplish the objects of obtaining high sensitivity, high contrast, less residual color and excellent positive image sharpness.

The photographic silver halide emulsion is a dispersion of silver chloride, silver chlorobromide, silver bromide, silver iodobromide, silver chloroiodide or silver chloroiodobromide in gelatin or a hydrophilic organic colloid as a protective colloid. A salt of metal belonging to Group VIII of the periodic table may be added to the emulsion during emulsification of the silver halide or during the physical ageing thereof, or a gold salt may be added during the formation of fogged nuclei. The above-described compound may be added in any step of the preparation process of an emulsion but most preferably is added after the formation of fogged nuclei and before the coating. The amount added, which depends on the emulsion used, preferably is from 0.1 to 10 g per 1 mol of silver halide.

In the invention, the combined use of known pinakryptol yellow or phenosafranine as a desensitizer, and a sensitizing cyanine dye in addition to the above described compound results in good effects.

Preparation of the direct positive photographic silver halide material according to the invention is carried out by subjecting a silver halide emulsion obtained through conventional emulsification and physical ageing to a known procedure such as radiation of light or addition of a reducing agent, for example, formaldehyde, hydrazine or thiourea dioxide whereby fogged nuclei are formed, and applying to a support member, such as a cellulose acetate film, a polyethylene terephthalate film, a baryta film or a synthetic paper followed by drying. Conventionally used photographic additives such as hardener and surfactant may be used.

The direct positive photographic silver halide material of the invention, as will be evident from the following examples, has a high sensitivity and an excellent image sharpness and a high contrast. Moreover, it is free from residual colors.

The following examples are given to illustrate the invention in greater detail without intending to limit it.

EXAMPLE l To a 10 percent aqueous solution of gelatin were added simultaneously an aqueous solution containing 100 g of silver nitrate and an aqueous solution containing 6 g of sodium chloride and 70 g of potassium bromide and reacted at 50C to form fine grains of silver halide.

Thereafter, 1 g of potassium iodide and 40 g of gelatin were added and the, pH was adjusted to 9.5 with sodium carbonate.

Five ml of 1 percent hydrazine hydrochloride was added and aged at 50C for 40 minutes to form fogged nuclei. After ageing, the pH was adjusted to 6.0 with i0 percent citric acid. After cooling and washing with water, Coloring Matter A (Compound of the Invention) and Coloring Matter B were added as shown in Table l. At the same time, pinakryptol yellow (Coloring Matter C) and 5,525, 6-dibenzo-3,3'-diethyloxacarbocyanine iodide (Coloring Matter D) were jointly used. Comparison samples were prepared by using Coloring Matter B or Coloring Matter C alone or in admixture in a similar manner.

Coloring Matter A S02NH4 S03 Hacl NHz Coloring Matter B N112 Coloring Matter C Coloring Matter D Amount Added (g/mol Ag) Coloring Matter Emulsion No. A B C D Each of the above described emulsions was coated onto a cellulose acetate film and dried. The resulting direct positive photographic silver halide material was exposed for 5 seconds using a tungsten bulb as a light source at 2660K through an optical wedge for sensitometry and then developed at 20C for 3 minutes with the following developer. The sensitivity, resolving power, gradation and residual color of the resulting sample are shown in Table 2.

Composition of Developer Sensitivity: Log E of fog density density [.0 Resolving Power: Using the measurement method of resolving power of the Koana type Gradation: average gradient between Point (fog density density 0.] and Point (fog density density 2.0)

It is evident from Table 2 that the samples 4, 6 and 9 containing Coloring Matter A according to the invention give excellent resolving power, high sensitivity and high contrast and residual color free features.

EXAMPLE 2 Three gelatin solutions were prepared from 100ml of a percent gelatin solution with addition of Coloring- Matter A (Compound of the Invention) or Coloring Matter B so as to give a same extinction density for a light of 550 mg, or without addition thereof.

Each of these solutions was coated onto a base member of cellulose triacetate film to give a thickness of 2 microns and dried to form a first layer for antihalation.

Emulsion No. 7 of Example 1 was further coated onto the first layer to give a thickness of 3 microns and dried. The resulting samples were tested in the same method as that of Example 1 to obtain results as shown It is evident from Table 3 that the use of Coloring Matter A in the first layer gives a high resolving power, a high contrast and residual color-free positive.

EXAMPLE 3 When using Coloring Matters F8 in place of Coloring Matter A in Examples 1 and 2, substantially similar results were obtained.

What is claimed is:

l. A spectrally sensitized direct positive photographic silver halide material containing in a layer of a uniformly fogged silver halide emulsion and/or in a layer adjacent said layer of a uniformly fogged silver halide emulsion a compound represented by the following general formula (I) in which R may be the same or different and is selected from the group consisting of H, CH C H and R is selected from the group consisting of H, CH and Cl and S is selected from the group consisting of SO H, and the alkali metal salts thereof and the ammonium salt thereof, and wherein the number of S substituents ranges from 1 to 3, the amount of said compound being effective to increase the reversal sensitivity of said uniformly fogged silver halide emulsion.

2. The direct positive photographic silver halide material of claim 1, containing pinakryptol yellow in addition to the compound represented by General Formula 7 3. The direct positive photographic silver halide material ofclaim 1, containing a cyanine or a merocyanine sensitizing dye in addition to the compound represented by General Formula (I).

4. The direct positive photographic silver halide ma-' terial of claim 1, containing pinakryptol yellow and a cyanine or a merocyanine sensitizing dye in addition to the compound represented by General Formula (I).

5. The material of claim 1 wherein from 0.1 to 10 g per one mol of silver halide of said compound is added.

6. The material of claim 1 wherein said silver halide is selected from the group consisting of silver chloride, silver chlorobromide, silver bromide, silver iodobromide, silver chloroiodide or silver chloroiodobromide in gelatin or a hydrophilic organic colloid.

7. The material of claim 1 wherein said compound is I a? (H f 803" C I SOJNIII 

2. The direct positive photographic silver halide material of claim 1, containing pinakryptol yellow in addition to the compound represented by General Formula (I).
 3. The direct positive photographic silver halide material of claim 1, containing a cyanine or a merocyanine sensitizing dye in addition to the compound represented by General Formula (I).
 4. The direct positive photographic silver halide material of claim 1, containing pinakryptol yellow and a cyanine or a merocyanine sensitizing dye in addition to the compound represented by General Formula (I).
 5. The material of claim 1 wherein from 0.1 to 10 g per one mol of silver halide of said compound is added.
 6. The material of claim 1 wherein said silver halide is selected from the group consisting of silver chloride, silver chlorobromide, silver bromide, silver iodobromide, silver chloroiodide or silver chloroiodobromide in gelatin or a hydrophilic organic colloid.
 7. The material of claim 1 wherein said compound is selected from the group consisting of: 